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    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
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    <script>
        // ## 1. 给一段文章中的全部指定词语进行过滤
         // 比如我要过滤 "SM"
   
        
        
        // 需要结果
        // asdasd**asdasdasd**sdasdasd**

        var str = 'asdasdSMasdasdasdSMsdasdasdSMsadaad'

        while(str.indexOf('SM') !== -1){
            str = str.replace('SM','**')
        }

    </script>
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